**6. Instructions to patient before the procedure: improving reproducibility**

The OGTT results can be affected by carbohydrate intake and duration of fasting preceding the test, time of day for the test to be performed or activity during the test, sample collection, and medications. Instructions are as follows:

1.Patient must be on meal containing >150 g carbohydrate (approximately ten 40 g slices of bread per day) in the last three days before the test, and in the night before the test should take 30-50 g of carbohydrate containing meal

(296 ml) bottles containing 50, 75, or 100 g of glucose (5, 7.5, and 10 g per

a. Once patient arrived, confirm compliance with preparations, with emphasis on duration of

b. You may wish to put in place an indwelling drip for sampling to avoid the stress of repeated

d. Take sample for fasting and any other investigations intended, before ingestion of glucose

e. Constitute the glucose solution—75 g(anhydrous) and 82 g(monohydrous)—10% more of

i. Same type of sample must be taken throughout the procedure(, venous or capillary)

n. Label samples appropriately, place sample ice-water slurry and ensure separation within

g. Time 0 minute of the test is when patient start taking the glucose solution and not when fasting

9. If patient is under unavoidable stress, the test should be postponed

provided with suitable training and are assessed to be competent (**Table 5**).

11.Failure to comply with all instructions will invalidate result

**7. Interpreting OGTT result: improving reproducibility**

**7.1 Considerations when interpreting OGTT result**

10.Patient should be aware of being seated in waiting area for a minimum of

Ensure that all staff involved in undertaking any elements of the test have been

When interpreting the result remember that OGTT has variable reproducibility and care should be taken not to over-interpret the results. Use only one criterion, eg WHO criteria, to indicate a diagnosis of IFG, IGT or diabetes. In most cases the results of fasting and 2-hr post-glucose load are enough. Always look for help from local diabetes serves in uncertainty. Refer cases you can not evaluate to endocrinologist for further for assessment. Usually there are no causes of false-positive result when processes are strictly followed. These arts will improve the reproducibility.

**7.2 While interpreting OGTT result you will not get information concerning**

a. Patient preparation for and how the glucose was administrated.

fluid ounce)

**Table 5.**

**127**

fasting

solution

sample is taken

period of the test

30 min of sampling

*Conduct of OGTT in a non-pregnant adult.*

needle pricking during sampling

*DOI: http://dx.doi.org/10.5772/intechopen.96549*

anhydrous glucose, in 250–300 ml

c. Ensure patient is comfortable before starting the procedure

*Oral Glucose Tolerance Test (OGTT): Undeniably the First Choice Investigation…*

h. Take samples at 30 minutes interval for 2 hr.(3, 5 hrs) or at 2 hr. only

j. No smoking, caffeine, alcohol or any exercise during the waiting period k. Monitor patient especially when approaches convenience—patient may vomit l. Should the patient sit, lie, stand, walk, talk, etc.(seating is preferred—minimal activity) m. Only minimal activity is allow but ensue that patient remain comfortable throughout the

f. Ask the patient to take the solution within 5 minutes

2 hrs for the test


#### **Table 5.**

education and preparation. Interacting with patient is important in improving

a. Enable the caregiver know about the patient—classify patient according to

b. Educate patient about why he/she is coming for the tests, and emphasize on what to avoid during pre-test period, and make patient to understand his/her

c. Know types of medications patient is on and withdraw those possible and

d. Emphasize the importance of patient's compliance and the result outcome

**6. Instructions to patient before the procedure: improving**

The OGTT results can be affected by carbohydrate intake and duration of fasting preceding the test, time of day for the test to be performed or activity during the test, sample collection, and medications. Instructions are as

1.Patient must be on meal containing >150 g carbohydrate (approximately ten 40 g slices of bread per day) in the last three days before the test, and in the night before the test should take 30-50 g of carbohydrate containing

2.No strenuous exercise three days prior to test, but normal work is allowed. Patient should not rush when coming for the test (avoid stress). Need to rest

before for minimum of 15 minutes before conducting test

3.No alcohol or Caffeine use 48 hrs before the test and during the test

5.Time for the test (morning hour is preferred, convenience of overnight fast, and fluctuation in FPG-higher in the morning and lower in the

6.Maximum 75 g, anhydrous (82 g monohydrate) glucose dissolved in

sometimes lucozide (375 ml) can be used instead.

7.Glucose solution ingestion within the shortest possible time—usually within 5 minutes. Intolerance for sweet taste—patient may come with lemon juice,

8.Others are Glucola (224 ml) equivalent of 75 g anhydrous glucose. Polycal liquid (previously called Fortical) is used as the glucose load. 61.4 g maltodextrin/100 ml. Oral glucose solutions come in 10 US fluid ounces

4.Overnight fast (8-14 hr) water is allow—for patients convenience

e. This interaction will prepare patient's mind and will alleviate fears and stress

reproducibility of test for the following reasons:

*Type 2 Diabetes - From Pathophysiology to Cyber Systems*

role in obtaining good result

**reproducibility**

follows:

meal

evening)

**126**

250–300 ml of water

the three categories of tests mentioned earlier

record those which cannot be withdrawn

*Conduct of OGTT in a non-pregnant adult.*

(296 ml) bottles containing 50, 75, or 100 g of glucose (5, 7.5, and 10 g per fluid ounce)


11.Failure to comply with all instructions will invalidate result

Ensure that all staff involved in undertaking any elements of the test have been provided with suitable training and are assessed to be competent (**Table 5**).
